0x1.relative_identifier(
  0x2,
  key: 0x3
)
0x1.relative_identifier(
  0x2,
  key: 0x3
)(
  0x4,
  key: 0x5
)
0x1.relative_identifier key: 0x2
0x1.relative_identifier unqualified 0x2,
                                    key: 0x3
0x1.relative_identifier 0x2,
                        key: 0x3